問(wèn)題描述

js怎么實(shí)現(xiàn)jq的addclass,removeclass,例如本來(lái)是 class='aa',要變成class='aa bb',注意不用jquery

問(wèn)題解答

js有個(gè)classlist的接口MDN鏈接

不過(guò)你要考慮下兼容性。

replace

if (!this.hasClass(obj, class)) obj.className += ' ' + class;

elem.className或者elem.classList感覺(jué)classList比較好，elem.classList.add(’bb’)就可以了另外，jQuery源碼是通過(guò)className實(shí)現(xiàn)的addClass和removeClass最后加一句，這種偏基礎(chǔ)的問(wèn)題要學(xué)會(huì)自己百度google

function addClass(ele,name){if(ele && name){ var cn = ele.className; if(!cn){ele.className = name; }else if(cn.indexOf(name) === -1){ele.className = cn.replace(/s*$/,’ ’+name); }}}function removeClass(ele,name){var reg1 = new RegExp(’^s*b’+ name +’bs*$’);var reg2 = new RegExp(’^s*’ + name+’b’);var reg3 = new RegExp(’b’+ name + ’s*$’);var reg4 = new RegExp(’s*b’+name+’bs*’);if(ele && name){ var cn = ele.className; if(cn && cn.indexOf(name) > -1){if(reg1.test(cn)){ ele.className = ’’;}else if(reg2.test(cn)){ ele.className = cn.replace(reg2,’’);}else if(reg3.test(cn)){ ele.className = cn.replace(reg3,’’);}else{ ele.className = cn.replace(reg4,’ ’);} }}};